Main Menu

A66 Challenger Registry

Started by 340challconvert, February 09, 2020, 08:14:25 AM

Previous topic Next topic

0 Members and 2 Guests are viewing this topic.

6bblgt

plenty of "J" heads for 1970 340s - just none of them during calendar year 1969 (where the changeover from "X" cast #2531894 to "JUO"  cast #3418915 is the question)

kawahonda

#61
Quote from: 6bblgt on June 27, 2020, 01:36:16 PM
plenty of "J" heads for 1970 340s - just none of them during calendar year 1969 (where the changeover from "X" cast #2531894 to "JUO"  cast #3418915 is the question)

Yep, and if 100% true, I have myself a conundrum when I rebuild my 340, which has J-heads. My guess is the owner had a "head rebuild" and they just used off-the-shelf J-heads. Do I invest a boatload of money in X-heads (which are not any better as long as the J heads have 2.02 valves), or just refurbish my current heads. Current engine has great compression. How important is it to see that "X" for a 1970 Challenger that was built in November '69?

How far down the rabbit hole do you want to go. I guess that's for me to answer. It doesn't make sense paying $1000 for rusted "X" heads that are not better than what I have. Ugh. At some point, the history of the car becomes more important than A66 history. The man had a head rebuild and the shop used "J" heads. That's part of the car's history, which I have documented more than A66 history. Slapping on "X" heads erases that.

My thought is that the "J" heads belong on the car, and will stay..even with a blue-printed rebuild.
1970 Dodge Challenger A66

340challconvert

#62
Quote from: kawahonda on June 27, 2020, 10:47:08 PM
Quote from: 6bblgt on June 27, 2020, 01:36:16 PM
plenty of "J" heads for 1970 340s - just none of them during calendar year 1969 (where the changeover from "X" cast #2531894 to "JUO"  cast #3418915 is the question)

Yep, and if 100% true, I have myself a conundrum when I rebuild my 340, which has J-heads. My guess is the owner had a "head rebuild" and they just used off-the-shelf J-heads. Do I invest a boatload of money in X-heads (which are not any better as long as the J heads have 2.02 valves), or just refurbish my current heads. Current engine has great compression. How important is it to see that "X" for a 1970 Challenger that was built in November '69?

How far down the rabbit hole do you want to go. I guess that's for me to answer. It doesn't make sense paying $1000 for rusted "X" heads that are not better than what I have. Ugh. At some point, the history of the car becomes more important than A66 history. The man had a head rebuild and the shop used "J" heads. That's part of the car's history, which I have documented more than A66 history. Slapping on "X" heads erases that.

My thought is that the "J" heads belong on the car, and will stay..even with a blue-printed rebuild.

Just some information on X  Heads, really no big advantage of one over the other:894 heads:
1} ~ #2531894 'X-Head'................July 1967 - thru - October 1970 'Casting'
Note; Called the 'X-Head'

Note; Generally considered the 'best' 340 Cylinder Head. Consistent 'Port Measurements' of 160 CC's Intake and 70 CC's Exhaust.
Note; The 'tightest' Combustion Chambers with levels between {67.0 to 69.0 CC's}.
Note; The 'X-Head' has the best Intake CFM Flow at High RPM's.

2} ~ #2531894 'X-Head'........................ October 1970 - thru - June 1971 'Casting'
Note; Also with consistent 'Port Measurements' of 160 CC's Intake and 70 CC's Exhaust.

Note; These later 'X-Head' Castings will have approximately +2.0 CC greater Combustion Chamber volume, usually between {69.0 to 72.0 CC's}.
Note; When these later Castings were machined by the Factory, less material was removed from the Head Deck Surface than early Castings.
Note; This was done to lower the 340 Engine's Compression Ratio from 10.5-1 to 10.3-1 to meet the EPA's Emissions at lower RPM's.


Data Moderator A66 Challenger Registry

Owner of 1970 A66 Challenger convertible


340challconvert

x heads vs others;

1968-1969-(first half) 1970 model year 340s used "X" heads cast # 2531894 with 2.02"/1.60" valves

(second half) 1970-1972 model year 340s used "J", "O", "U", "Z" heads cast # 3418915with 2.02"/1.60" valves (at some point & on 360s with 1.88"/1.60" valves)

340+6 T/A heads are "J", "O", "U", "Z" heads cast # 3418915 with offset intake pushrod holes and 2.02"/1.60" valves

1973 model year 340s used heads cast # 3671587 with 1.88"/1.60" valves (also used on 360s)


Data Moderator A66 Challenger Registry

Owner of 1970 A66 Challenger convertible

340challconvert

Going back into an old file; found a beautiful A66 y1, 4 speed car with a black interior and black bumble. Car has pdb, and chrome Magnum 500 wheels w e60-15 tires and Black out hood. Sold for a very reasonable $35K in the April 2014 Mecum auction


Data Moderator A66 Challenger Registry

Owner of 1970 A66 Challenger convertible

Mark_B

Here's a shot of my A66 with some new deeper dish 15x8  TT's.

Mark
www.dodgechallenger.uk

340challconvert

Quote from: Mark_B on July 23, 2020, 02:05:58 AM
Here's a shot of my A66 with some new deeper dish 15x8  TT's.

Looking really good. I like the stance of the car with the deep dish wheels! :drinkingbud:
The RT style side stripe really sets the car off.


Data Moderator A66 Challenger Registry

Owner of 1970 A66 Challenger convertible


340challconvert

The A66 Registry now has full or partial data on 129 A66 cars.
I drill down as specific as possible on option details so that I can determine percentages of certain details. I am started to see patterns in color selections, when V8 emblems were used, when hood decals/metal callouts were started/ended, ratio of automatics to 4 speeds, build dates, percentages of cars with the A62 rallye dash, how many of our cars came w factory AC, what type of radio was factory installed, how many factory hood pin cars?, how many rare WSS A66 Challengers were made?.
This is just part of what I track. As always; registering your car will help the information grow. Thank you[    :driving:


Data Moderator A66 Challenger Registry

Owner of 1970 A66 Challenger convertible

Mark_B

Thanks.  I used a none designated stripe, so it's not pretending to be an R/T.
Mark
www.dodgechallenger.uk

DeathProofCuda

@ Mark_B, great looking car.  Can you post some pics showing the side view with the new TTs?  I'm thinking about getting some day-2 wheels for my car and keep going back and forth between Torq Thrusts and slots. 

Mark_B

#70
Here we go.
Mark
www.dodgechallenger.uk


DeathProofCuda


340challconvert

A66 Go Mango/orange interior 4 speep, Project car For Sale with most parts going with it. Non original motor. Chassis looks very clean and needs assembly. Car is in Texas

http://topclassiccarsforsale.com/dodge/414635-rare-1970-dodge-challenger-340-4-speed-a66-package-car-rare.html



Data Moderator A66 Challenger Registry

Owner of 1970 A66 Challenger convertible

340challconvert

Would love to see the tag on this one!  N96 would be a coup! :wrenching:


Data Moderator A66 Challenger Registry

Owner of 1970 A66 Challenger convertible

benlavigne

Not an original N96, unfortunately! Not a very long window of opportunity to get a Shaker on an A66, as it was made available on April 13, so less than three months... Have not seen any yet, @6bblgt , any numbers on N96 production, combined with A66?
THis one does have C15 Deluxe Belts, also a rare option!

Ben